Gailliot et al (2007) found that reduced self-control, caused by thinking of of mortality (cf. dental pain), impairs word-puzzle persistence under placebo conditions. This deficit was eliminated in subjects who had consumed a glucose drink.

Subjects were randomly assigned to consume either a placebo (lemonade made with water and lemons, plus Splenda sweetener), or lemonade plus 140 calories of glucose instead of the Splenda. Both drinks were 14oz.

They then completed two measures of liking for the drink, followed by filler questionnaires and a crossword for 12min to allow its absorption.

Next they wrote about one of two topics for 5min. For mortality salience they wrote about what would happen to their body after death, and their emotions. For dental salience they wrote about how their body reacts to dental pain, and their emotions.

They were then given a sheet with 20 word fragments (words were selected randomly from the dictionary) and allowed 10min to solve them (e.g. ___ATULA). They were scored for the number of word fragments that were left uncompleted, out of 20.

Finally they estimated how many calories there were in the drink they had consumed.

An independent groups t-test showed that under mortality salience conditions, fewer words were left after drinking glucose than after placebo, t(156) = 2.33, p = .010. However, with dental pain salience, there was no difference due to the drinks, t(146) = .93, p = .17.

These results support the findings of the target article: glucose compared to placebo increased subjects' self-control, shown as fewer words left uncompleted.

Any Known Methodological Differences (between original and present study)?

No differences are known (except that the Marlowe-Crowne Social Desirability Scale was not given after testing).
A 10 min period was used for consumption of the assigned drink (unspecified duration in the original report).
The lemonade used 1 sliced lemon per 56 oz water, plus a packet of Splenda in the placebo condition or 800g glucose per 8L water in the experimental condition.

Email of Investigator

Name of individuals who actually carried out the project

The data were analyzed by L.Standing, and were collected by the remaining authors.

Location of Project

Nicolls 316, Bishop's University

Characteristics of Subjects (subject pool, paid, etc.)

University students from subject poolUnpaid volunteers, undergraduate psychology students. 68% were female.